This invention relates to a process for producing a polyimide-amide-carboxylic acid, more particularly to a process for producing a polyimide-amide-carboxylic acid containing imide rings, amide linkages and carboxylic acid moieties in the polymer chain.
There are known the following references in this art; i.e. Japan JAP. PAT No. 676-7/67 (Derwent Jap. Pat. Report) (1967), J. Applied Polymer Science vol. 19, 2961-2980 (1975) and J. Polymer Science 7, 2757-2762 (1969).
The polyimide-amide-carboxylic acids obtained by this invention are good in heat resistance, wear resistance, chemical resistance, etc., and are useful for preparing electrical insulating materials, various molding materials, films, adhesives, paints and varnishes, and the like.